This is my theory on how you can figure out most of the time how mature, or not mature a person is going to be, including grammar, spellings and behaviour.
Capitals, Numbers
Capitals and / or numbers in their name generally results in the acts of a "dork" / "idiot" / "child enthusiast"
Including These Words In Their Name
Including this list of names generally makes them a "dork", an "idiot" etc. :
~Halo~
~Killer~
~Master Chief~
~Master~
~Cool~
~Epic~
~Awesome~
~Ownsome~
~Pwnsome~
~Cool~
~Girl~
~Hot~
~Chick~
~Dude~
~Super~
~Mario~
If there are more needed to this list, then please tell me.
Bad Grammar In Names
Ussually makes them an idiot / dork / child enthusiast.
P.S. If you're going to take out the "capitals" thing on me, then I'll have you know, that I used to be named LFOO. When I changed to Lfoo, I was cool cooler.